1. Technical Field
The present invention relates to rateless coded transmission and, in particular, to systems and methods for information retransmission using rateless codes.
2. Description of the Related Art
Rateless codes, such as Luby-Transform (LT) codes, are commonly used for data transmission without feedback information. In a rateless code, transmission of a piece of information (rateless coded bits or symbols) can continue indefinitely, until such time as the receiver has enough information (rateless coded bits or symbols) to decode the information (original data bits or symbols before encoding). In such a code, there is no fixed proportion between the amount of information sent to the amount of information encoded—hence the term “rateless.”
If limited feedback is allowed in a rateless coded system, the system can convey a certain amount of information to the transmitter to improve the data recovery performance. In particular, the receiver may request retransmission in a process called “doping.” However, extant doping systems are wasteful, having unnecessarily high doping rates that result in wasted retransmissions.